The house had been put up for �20K over the market value

The house in Mivart Street in Easton which had been on the market for offers over �160,000 has now been withdrawn from sale.

Owner Sarah Anslow of Devon said she was "gutted" by the news.

"We'll see if we can get it restored - if you can restore an oil painting then why not graffiti?" she said.

'Such a shame'

"We're going to ask Banksy if he'd help us get it restored then we'll try to protect it but I'm not sure how yet," said Ms Anslow.

"There are paints you can use to stop graffiti being sprayed onto walls so maybe that will protect the original mural.

"It's such a shame as the whole point was to protect the mural."

The free-painted artwork on the side of the terraced property, and accessible from the street, is believed to be one of the artist's early pieces, dating to around 2002.

The house and the mural are being sold as a package

It was daubed with red paint sometime between Wednesday evening and Thursday morning.

Estate agents Ocean who were handling the sale have been to the property on Friday morning to see the damage.

People who submitted sealed bids will be informed that the sale has been withdrawn.

Banksy's art has become very desirable among fashionable collectors with Angelina Jolie and Christina Aguilera among those who are reported to have bought his work.

But it's not the first time one of his murals has been defaced.

Mural stolen

Workers on the London Underground painted over a Pulp Fiction-inspired piece earlier this month after mistaking it for ordinary graffiti.

And in March, a mural in east London was almost entirely removed by thieves.

One of Banksy's early murals was mistakenly painted over in the same month by Bristol City Council's graffiti-removal contractors.

And in February two smaller works in London were also painted over.